The shop that did the install is very reputable and has done many UUC SSK installs before. They were also confused as to why the shifter sat so high. Sounds like the DSSR not fitting is a typical BMW mid-year (or mid-whatever) part change issue.

I too had troubles with UUC SSK and DSSR. The SSK was assembled incorrectly and caused installation problems. They did send one correctly assembled. Because the DSSR was not ready yet, the DSSR came later and when it was installed it impinged on an adjacent part (I can't remember what now) and it had to be bent to install without binding. So it was an overall poor experience for me. I do like it, but not sure I would deal with them in the future.

I bought a UUC SSK with DSSR for my E39 530i. In this case, the DSSR had to have one of the corners ground down in order to work properly. I also spoke to Rob about it and he acknowledged the problem as if he knew it before I even asked about it. So why don't they grind it down themselves instead of letting us spend hours trying to do their engineering for them. The SSK worked as advertised and the height with the ZHP knob on my 5 series helped turn it from "rowing a boat" to something closer to my Z4M. I'm definitely NOT sold on their customer service.

As for the Z4M, I have the ZHP knob as well which for me gives very short shifts and I see no need for this mod on the M. YMMV.

Quick update. I got home from work finally on Sunday night. Emailed Rob the height of the top portion (adjustable part) of the assembly, as he requested, first thing Monday morning. Have yet to hear anything. I'm trying very hard not to be irritated.

The engineer who did the original designs for UUC years ago left the company a long time ago! Hence, nothing has been updated to newer, better technology. If they come out with a new product, it's based on the old design. Not good.
I have a Rogue Engineering SSK in my 330 for 5-1/2 years with zero issues.